@article{CM_1968__20__70_0, author = {Goodstein, R. L.}, title = {Existence in mathematics}, journal = {Compositio Mathematica}, pages = {70--82}, publisher = {Wolters-Noordhoff Publishing}, volume = {20}, year = {1968}, mrnumber = {224413}, zbl = {0162.30901}, language = {en}, url = {http://archive.numdam.org/item/CM_1968__20__70_0/} }